Version Control - Univerzita Karlova...svn proplist svn propget svn propedit Locks Nástroje pro vývoj software Version Control 24 Still needed to work with binary files Merge not

CHARLES UNIVERSITY IN PRAGUE

http://d3s.mff.cuni.cz

faculty of mathematics and physics

Version Control(Správa verzí)

Pavel Parí[email protected]

What is it good for ?

Nástroje pro vývoj software Version Control 2

Keeping history of system evolution

Tracking progress

Allowing concurrent work on the system

Teams of developers

Possible conflicts

Easy reverting to a previous version

Safer experimentation

Typical architecture


Source code repository(versioned sources)

Working copy

synchronization

Working copy

Basic usage scenario


Source coderepository

Working copy

check-out or update1.

2. modify & test

3.add & check-in

Categories of versioning systems


Centralized

CVS: Concurrent Versioning System

The “classic” system

SVN: Subversion

Currently still used by many open-source projectshttp://apache.org/index.html#projects-list

Distributed

Git, Mercurial, Bazaar

http://apache.org/index.html#projects-list

Branches and merging


main line of development (master branch)

concurrent development (experimenting)

branching merging

time & software versions

bug fix in released version

branching

NOW

Conflicts


Options

Postpone resolving

Choose version

External merge tool

and many others

Conflict markers

<<<<<<< and >>>>>>> in source file

Three variants of the source file created

Tree conflicts


Typical cause

Renamed files and directories

Deleted files

Solution

Make proper changes in the working copy

Use patches created with the diff command

Commit when everything is in a clean state

Tags


Snapshot with a human-friendly name

Logical copy of the whole source tree

Best practices: synchronizing developers


Software developed in large teamsPeople may not be always able to coordinate efficiently

Solution: Copy-Modify-MergeConcurrent modification of source filesResolving conflicts when they happen

Alternative: Lock-Modify-UnlockThe old classic approach (“before internet”)Does not scale well (exclusive access)Not very robust (people forget to unlock)

Best practices: branches and merging


Use branches for experimental features

Create special branch for each feature

Separate release and development branches

Propagating bugfixes from development to stable

Merge often and synchronize with trunk

Lower chance of ugly conflicts occurring

Smaller conflicts are easier to resolve

Commit often others will have to merge

Subversion


Important features


Whole source tree versioned

Integer numbers (1,2,3,...)

Mixed versions in the working copy

Atomic commits

Versioning for files and directories

Operations: move, rename, delete

Support for binary files

Disconnected operations

Metadata in “.svn” directories

Locations


Repository

Remote server (svn+ssh://<network url>)

Local directory (file://<absolute path>)

Working copy

Local directory on your computer

Basic commands


Help: svn help <command>

Create new repository: svnadmin create

Create new working copy: svn checkout

Update working copy: svn update

List modified and new files: svn status -v

Show differences between repository and working copy (two versions): svn diff –r<version>

Use svn diff -r<v1>:<v2> to see differences between two specific versions

Add new files into repository: svn add

Commit changes: svn commit –m “...”

Display information about file: svn info

Few more useful commands


Undo changes in working copy: svn revert

See full history of a given file: svn log

Importing whole unversioned tree into repository: svn import <dir> <repo>

Exporting content of the repository without metadata: svn export

Managing files and directories


Commandssvn add <path>

svn delete <path>

svn copy <path1> <path2>

svn move <path1> <path2>

svn mkdir <path>

PathIn your local working copy

Repository (auto-commit)

Branching and merging – commands


Create new branchsvn copy <main line repo path> <branch repo path>

Print differencessvn diff <main line repo path> <branch repo path>

Make your branch up-to-date (sync merge)svn merge <main line repo path>

svn merge ^/<main line repo dir>

Merge branch into the main line (trunk)svn merge --reintegrate ^/<branch repo dir>

Previewsvn merge <repo path> --dry-run

Undoing committed modifications


Merge negative version range into local working copysvn merge <repo path> -r <v1>:<v2>

Note: v1 > v2

Commit everything

Cherrypicking


Merge specific change into your branchsvn merge -c <version> <repo path>

Commit your branch

Standard repository layout


/trunk/branches/tags

/project1/trunk/project1/branches/feature1/project1/tags/project2/trunk/project2/branches/project2/tags/R_1_0/project2/tags/R_1_2_1

Revision keywords


HEADLatest version in the repository

BASERevision number in the working copy (before modifications)

COMMITTEDThe latest revision in which the item changed and was committed (not larger than BASE)

PREVEqual to COMMITTED-1

Properties


Standard name-value pairsMany internal system properties

svn:ignore, svn:eol-style, ...

Setting property valuesvn propset <name> <value> <path>

svn propset <name> -F <file> <path>

Other commandssvn proplist

svn propget

svn propedit

Locks


Still needed to work with binary files

Merge not supported for concurrent modifications

Lockingsvn lock

Unlockingsvn commit

svn unlock

Inspectingsvn info

GUI clients for SVN


Tortoise SVN (Windows)

http://www.tortoisesvn.net

Eclipse IDE

Other

kdesvn (Linux)

svnx (Mac OS)

Links


http://subversion.apache.org

SVN Book

http://svnbook.red-bean.com

Documents

Version Control - Univerzita Karlova...svn proplist svn propget svn propedit Locks Nástroje pro vývoj software Version Control 24 Still needed to work with binary files Merge not